<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>10focus伪类选择器</title>
    <style>
        /* 把获得光标的input表单元素选取出来 */
        
        input:focus {
            background-color: pink;
        }
    </style>
</head>

<body>
    <h3>用于获取获得焦点的表单元素input:focus</h3>
    <input type="text">
    <input type="text">
    <input type="text">
</body>

</html>